全文获取类型
收费全文 | 772篇 |
免费 | 109篇 |
国内免费 | 1篇 |
专业分类
林业 | 55篇 |
农学 | 41篇 |
基础科学 | 10篇 |
112篇 | |
综合类 | 58篇 |
农作物 | 33篇 |
水产渔业 | 83篇 |
畜牧兽医 | 447篇 |
园艺 | 8篇 |
植物保护 | 35篇 |
出版年
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 28篇 |
2020年 | 21篇 |
2019年 | 36篇 |
2018年 | 41篇 |
2017年 | 34篇 |
2016年 | 25篇 |
2015年 | 30篇 |
2014年 | 40篇 |
2013年 | 49篇 |
2012年 | 43篇 |
2011年 | 47篇 |
2010年 | 33篇 |
2009年 | 24篇 |
2008年 | 35篇 |
2007年 | 24篇 |
2006年 | 29篇 |
2005年 | 30篇 |
2004年 | 20篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 18篇 |
2000年 | 22篇 |
1999年 | 19篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1977年 | 4篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1970年 | 2篇 |
1968年 | 5篇 |
排序方式: 共有882条查询结果,搜索用时 31 毫秒
21.
Immunostimulatory effects of dietary poly‐β‐hydroxybutyrate in European sea bass postlarvae 下载免费PDF全文
Andrea Franke Catriona Clemmesen Peter De Schryver Linsey Garcia‐Gonzalez Joanna J Miest Olivia Roth 《Aquaculture Research》2017,48(12):5707-5717
The stable production of high‐quality fry in marine aquaculture is still hampered by unpredictable mortality caused by infectious diseases during larval rearing. Consequently, the development of new biocontrol agents is crucial for a viable aquaculture industry. The bacterial energy storage compound poly‐β‐hydroxybutyrate (PHB) has been shown to exhibit beneficial properties on aquatic organisms such as enhanced survival, growth, disease resistance and a controlling effect on the gastrointestinal microbiota. However, the effect of PHB on the developing immune system of fish larvae has so far not been investigated. In this study, the effect of feeding PHB‐enriched Artemia nauplii on survival, growth and immune response in European sea bass (Dicentrarchus labrax) postlarvae was examined. Amorphous PHB was administered to 28‐day‐old sea bass postlarvae over a period of 10 days. The survival and growth performance were monitored, and the expression of 29 genes involved in immunity, growth, metabolism and stress‐response was measured. While the expression of the insulin‐like growth factor 1 (igf1), an indicator of relative growth, was upregulated in response to feeding PHB, the larval survival and growth performance remained unaffected. After 10 days of PHB treatment, the expression of the antimicrobial peptides dicentracin (dic) and hepcidin (hep) as well as mhc class IIa and mhc class IIb was elevated in the PHB fed postlarvae. This indicates that PHB is capable of stimulating the immune system of fish early life stages, which may be the cause of the increased resistance to diseases and robustness observed in previous studies. 相似文献
22.
Equine intravenous glucose tolerance test: glucose and insulin responses of healthy horses fed grain or hay and of horses with pituitary adenoma 总被引:2,自引:0,他引:2
Intravenous glucose tolerance testing (0.5 g/kg of body weight) was done on 2 groups of healthy horses maintained with hay (group 1, n = 5) and with hay plus grain supplementation (group 2, n = 5) and on a group of horses with clinically diagnosed pituitary adenoma (group 3, n = 10). Healthy horses showed an immediate increase of plasma glucose concentration after the IV glucose injection, with return of values to base line in 1 hour. Group 3 horses showed resting hyperglycemia and a delayed return of glucose values to base line (3 hours). Group 3 horses showed resting hyperinsulinemia and a feeble (nonsignificant) response to the glycemic stimulus, with gradual decrease of insulin values to base line. In addition to the apparently reduced tissue sensitivity to insulin in group 3 horses, as evidenced by hyperglycemia, hyperinsulinemia, and protracted glucose and insulin curves, the initial decrease in the insulin/glucose ratio indicates that there was secretory deficiency in response to acute IV glucose loading. 相似文献
23.
Sixteen of 17 sheep with spontaneous listeric encephalitis had neuritis characterized by diffuse and focal intrafascicular and perineural accumulations of lymphocytes, plasma cells, macrophages and neutrophils in one or more cranial nerves. Nine sheep had extensive trigeminal neuritis which was usually unilateral. Brain lesions were mainly in the stem and were foci of macrophages or neutrophils or both, malacia, neutrophilic neuronophagia, vascular cuffing, and meningitis. Lesions in the brain and trigeminal ganglia were most severe on the same side as the affected trigeminal nerve. Gram-positive bacilli were in proximal parts of cranial nerves in foci of inflammatory cells and occasionally in morphologically intact nerve fibers. Organisms in the brain were in phagocytes in areas of inflammation and in scattered neurons and axons. The results were consistent with centripetal migration of the infectious agent along one or more branches of the trigeminal nerve to the brain and dissemination in the brain stem occurring, at least partly, along fiber tracts. Intraaxonal movement of bacteria probably is a mechanism involved in the pathogenesis of this disease. 相似文献
24.
Results of a Preliminary Trial with Sphaerophorus necrophorus Toxoids to Control Liver Abscesses in Feedlot Cattle 总被引:1,自引:1,他引:0 下载免费PDF全文
M. M. Garcia D.C. Alexander K. A. McKay W. J. Dorward S. E. Magwood 《Canadian journal of veterinary research》1974,38(3):222-226
A preliminary field experiment was undertaken to evaluate the efficacy of alum precipitated toxoids of Sphaerophorus necrophorus prepared from sonicated whole cells and cell fractions to reduce the incidence of bovine abscesses. A total of 108 calves were divided into five groups and treated as follows: I. uninoculated control, II. adjuvant inoculated control, III. 15.5 mg protein of sonicated (fragmented cells) toxoid, IV. 10.5 mg protein of cytoplasmic toxoid. V. 15.5 mg protein of cytoplasmic toxoid. All animals were maintained under similar conditions to those prevailing in feedlots in Alberta. Livers were examined at slaughter. The most promising result was achieved with the injection of 15.5 mg protein of cytoplasmic toxoid. In this treatment group, no scars (healed lesions) were found in the liver and the incidence of liver abscesses was reduced to 10% from the average 35% liver abscesses and scars found in the uninoculated and adjuvant inoculated groups. The toxoid from sonicated whole cells did not reduce liver abscess incidence. These data suggest that the incidence of liver abscesses in cattle fattened in feedlots may be reduced by immunization. 相似文献
25.
Andaluz A Tusell J Trasserres O Cristòfol C Capece BP Arboix M Garcia F 《Veterinary journal (London, England : 1997)》2003,166(2):198-204
Propofol is an injectable anaesthetic that is currently used both in veterinary and human medicine for the induction and maintenance of anaesthesia. Although little is known about the pharmacokinetics of propofol in fetuses, it is widely used in obstetric procedures, particularly in caesarean section. This study determines the pharmacokinetics of propofol in pregnant ewes in the last third of pregnancy, and placental transfer and pharmacokinetics in fetuses after the administration of a 6 mg/kg intravenous (i.v.) bolus (phase 1) or a 6 mg/kg i.v. bolus followed by continued infusion of 0.4 mg/kg/min. In ewes, the area under the blood concentration-time curve (AUC) and C(max) (8.6 mgh/mL and 9.5mg/mL, respectively) was higher than those of the fetus (1.6 mgh/mL and 1.19 mg/mL, respectively). The mean half-life was 0.5h in the dam and 1.1h in the fetus. 相似文献
26.
Villarino MA Garcia O Fussell W Preston K Wagner GG 《Preventive veterinary medicine》2003,61(4):333-338
After the civil war and the Hurricane-Mitch disaster, cattlemen in Nicaragua were forced to transport their cattle from lowland areas to higher, dryer areas of the country. These areas are natural ecological niches for the cattle grub Dermatobia hominis (L. Jr.) (Diptera: Cuterebridae). To determine the importance of this infestation, the Agricultural and Livestock-Forestry Ministry selected a central area of Nicaragua to run a pioneer survey program to acquire information about hosts involved, number of cases, treatments applied and general knowledge of 42 farmers about the life cycle of the parasite. The subjects were either farm owners or farm managers. Ninety-five percentage of the farms indicated cases of D. hominis infestation in their animals, with cattle being the most affected host (100% of the affected farms). There was poor understanding of the D. hominis life cycle, vectors and control methods. A misuse of insecticides for the treatment of larval infestation by D. hominis was indicated. 相似文献
27.
Taenia solium oncosphere antigens induce immunity in pigs against experimental cysticercosis 总被引:11,自引:0,他引:11
Verastegui M Gilman RH Gonzales A Garcia HH Gavidia C Falcon N Bernal T Arana Y Tsang VC;Cysticercosis Working Group In Peru 《Veterinary parasitology》2002,108(1):49-62
Immunity to Taenia solium infection was investigated using an experimental intramuscular oncosphere infection assay (IMOA) model in pigs. Three naturally infected pigs with cysticercosis were treated with oxfendazole (OFZ), a drug demonstrated to kill cysts in porcine muscle. These animals were then challenged with oncospheres but did not develop any cysts while three uninfected pigs that were similarly challenged, did develop intramuscular cysts. In another study, two groups of three pigs each were immunized with crude T. solium oncosphere and metacestode antigens, respectively, and tested with the IMOA. Immunization with crude oncosphere antigens (OAs) induced 100% protection, while metacestode antigens provided only partial protection. Immunoblots showed that pigs with complete immune protection to oncosphere intramuscular challenge had antibodies to two OAs at 31.3 and 22.5 kDa, respectively. Antibody to these two antigens was absent in pigs immunized with metacestodes or in uninfected control pigs. This study demonstrated the presence of two antigens that are unique to the oncosphere. Although, antibody to these two antigens is consistently present in pigs that are protected from an oncosphere intramuscular challenge their role in preventing infection by T. solium larval cysts is still hypothetical. 相似文献
28.
Heinemann MB Garcia JF Nunes CM Gregori F Higa ZM Vasconcellos SA Richtzenhain LJ 《Veterinary microbiology》2000,73(4):261-267
In view of the importance of venereal transmission of bovine leptospirosis, the objective of the present study was to apply the polymerase chain reaction (PCR) to 26 serovars of Leptospira interrogans, L. borgpetersenii, L. santarosai, L. noguchii and L. biflexa, to determine the detection threshold in semen samples and to evaluate the possibility of differentiation among serovars using 19 restriction endonucleases. The results showed that all serovars were amplified and the detection threshold in semen samples of a bull was 100 bacteria/ml. Using endonucleases we could classify the 26 serovars into eight groups. The present results show that PCR is a method of great potential for the detection of Leptospira spp. at bovine artificial insemination centers. 相似文献
29.
García ME Caballero J Toni P Garcia I Martinez de Merlo E Rollan E Gonzalez M Blanco JL 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2000,47(4):243-249
We describe a case of canine mycoses initially diagnosed by clinical signs and enzyme-linked immunosorbent assay anti-fungal test, and later confirmed by the isolation of Paecilomyces sp. during the post-mortem examination. The fungus was isolated from lesions in the kidneys, mitral valve, abdominal aorta and vertebral discs. In this kind of process, it is important to identify the responsible agent early in order to make a study of anti-fungal susceptibility and establish effective treatment. 相似文献
30.
Verástegui M González A Gilman RH Gavidia C Falcón N Bernal T Garcia HH 《Veterinary parasitology》2000,94(1-2):33-44
A novel method for infecting pigs with Taenia solium using an intramuscular innoculum of oncospheres was investigated in a series of five experiments in 18 animals. The model is simple to perform, requires a minimal number of oncospheres, permits multiple infections per animal, and decreases the variation inherent in oral infection models. This intramuscular oncosphere assay (IMOA) may provide a valuable tool to evaluate therapeutic agents or potential vaccines for cysticercosis. 相似文献